Yawning may just be the most common but least understood behaviour. The purpose of this daily behaviour has long been of interest with many theories leading the way. In dogs, yawning is thought to have very different interpretations depending on when and where the yawn is taking place. Andrew Gallup et al report in “Biology Letters” states that the leading theory is that yawning awakens your higher processing areas by improving blood flow and brain cooling.
If that isn’t news to you perhaps you may find interesting that the length of your yawn has potential as a crude IQ test.
In his study Gallup measured the duration of yawns for 29 mammals and compared that to the brain weight and the number of neurons (i.e. all the little brain wires) for those mammals. It turns out that the duration of yawns is a neat little predictor of brain weight and the number of neurons. Primates were found to have the longest yawn with humans leading the way. Here’s a little fact you can quote over dinner tonight: with the most complex brains we yawn longer than camels, horses, lions, walruses and African elephants …. so when you yawn make sure it’s for longer than your furry companion.
Dr Kate Lindsey
Veterinarian and Animal Behaviourist
Kalmpets Animal Behaviour Centre